Hi my name is Robert...This sounds like it can be an issue with the cooling unit or thermistor if it is not cooling on both sources. A cooling unit can rupture or become blocked. For a rupture you might smell ammonia, see a yellowish powder on the back of the fridge OR hear a gurgle when you turn it on. For a blockage you might not have any symptoms at all but no cooling on both sources.The other issue is the thermistor that sits inside the fridge, if you have a volt meter you can test it out. Please let me know if you have a volt meter and I can explain how to test that....IF you have any other questions please feel free to contact me.... Robert

It would be better if you see the procedure, click HERE and see page 20. What you are going to do is dis-connect the connector for the light inside the fridge, it shares the same connector as the thermistor, then you stick the other end into the a cup of ice water for about 5 mins and then ohm the wires leading to the thermistor. Also on this make sure the top vent is clear and clean, with no cooling on both sources I would suspect the cooling unit is at fault if the thermistor checks out... IF you have more questions please feel free to contact me, IF you are satisfied with my efforts please feel free to select a rating, it is the only way I get credit... Robert